```bash
$ sudo add-apt-repository \
"deb [arch=amd64] {{ download-url-base }} \
$(lsb_release -cs) \
stable"
```
```bash
$ sudo add-apt-repository \
"deb [arch=armhf] {{ download-url-base }} \
$(lsb_release -cs) \
stable"
```
```bash
$ sudo add-apt-repository \
"deb [arch=arm64] {{ download-url-base }} \
$(lsb_release -cs) \
stable"
```
#### Install Docker Engine
1. Update the `apt` package index, and install the _latest version_ of Docker
Engine and containerd, or go to the next step to install a specific version:
```bash
$ sudo apt-get update
$ sudo apt-get install docker-ce docker-ce-cli containerd.io
```
> Got multiple Docker repositories?
>
> If you have multiple Docker repositories enabled, installing
> or updating without specifying a version in the `apt-get install` or
> `apt-get update` command always installs the highest possible version,
> which may not be appropriate for your stability needs.
2. To install a _specific version_ of Docker Engine, list the available versions
in the repo, then select and install:
a. List the versions available in your repo:
```bash
$ apt-cache madison docker-ce
docker-ce | 5:18.09.1~3-0~ubuntu-xenial | {{ download-url-base }} xenial/stable amd64 Packages
docker-ce | 5:18.09.0~3-0~ubuntu-xenial | {{ download-url-base }} xenial/stable amd64 Packages
docker-ce | 18.06.1~ce~3-0~ubuntu | {{ download-url-base }} xenial/stable amd64 Packages
docker-ce | 18.06.0~ce~3-0~ubuntu | {{ download-url-base }} xenial/stable amd64 Packages
...
```
b. Install a specific version using the version string from the second column,
for example, `5:18.09.1~3-0~ubuntu-xenial`.
```bash
$ sudo apt-get install docker-ce=